Git vs GitHub

Why GitHub?

1. A structured way for tracking changes to files over the course of a project.

2. Makes it easy to have multiple people working on the same files at the same time.

3. You can host a URL of fun things (like the class text, these slides, a personal website, etc.) with GitHub pages.

Think “track-changes” or “drop-box” history, but more structured.

Git Repositories

• Think of this as a folder-directory for a single project (like your stat-331 folder!)

• You may have code, documentation, data, TODO lists, and more associated with a project.

• To create a repository, you can start with your local computer first, or you can start with the remote (online) repository first.

Cloning a Repo

Committing

Git tracks changes to each file that it is told to monitor, and as the files change, you provide short labels describing what the changes were and why they exist (called “commits”).

The log of these changes (along with the file history) is called your git commit history. This means you can always go back to old copies!

Pushing

Pulling

Pushing and Pulling

Merge Conflicts

Occur when you make changes to the same line as a collaborator either at the same time, or without starting from the same “state”.

1. Maybe you are working in real time on the same line of code or text.
2. Maybe you forgot to push your changes last time you finished working.
3. Maybe you forgot to pull your changes before you started working this time.

Workflow

Workflow

Rpackages we will need

Work in your console or a .Rscript for this…

1. Install and load the {usethis} Rpackage

install.packages("usethis")
library(usethis)

2. Install and load {gitcreds} RPackage

install.packages("gitcreds")
library(gitcreds)

Configure git

3. Tell git your email and username.

use_git_config(user.name = "JaneDoe2", user.email = "jane@example.org")

Generate your PAT (Personal Access Token)

4. Generate token

create_github_token()

Store your PAT

5. Copy your PAT

6. Enter password or token: Paste PAT

gitcreds_set()

Verify PAT

You should be good to go! Let’s verify.

git_sitrep()

Get into your groups!

Designate each person to one of the suits – you will be referencing it as you work through this activity.

Flags

Please use sticky notes to indicate how your group is doing:

• Blue

  – We are ready to move on

• Yellow

  – We’re figuring it out

• Red

  – Please help!!

Creating a Repo (starting from GitHub)

• Create a new Github repository – Repositories > New
  • Name the repository stat-331-PA6
  • You can choose Public or Private
  • Select .gitignore template: R
• Click on the Settings tab > Click on Collaborators > Add people
• Add your other group members to the repository using their username or email

Accessing the Repo (remote repo)

• Verify repository invite in your email – View invite > Accept invite
• Open the repository in GitHub – github.com/

Cloning the Repo (local repo)

• In Rstudio File > New Project > Version Control > Git (pause)
• In GitHub, copy the HTTPS address from the repo <> Code and paste into Repository URL in RStudio
• Click Browse and navigate to where you want to create your new project. I recommend creating this on your desktop.

• Create Project

Adding Documents to the Repo

• Create a new Quarto file (using the standard template)
  • Title the document “Practice Activity 6”
  • Resist the urge to add author names
  • Save the document as PA6.qmd in your stat-331-PA6 desktop folder
  • Add self-contained: true to the YAML
  • Render the document
• Edit the .gitignore file to include *.Rproj

Pushing Documents to the Repo

• Git pane > Commit > Stage (or checkmark) files > Commit message > Commit
  • Commit both the .gitignore file with an explanatory message such as “Ignoring all .Rproj files in repo”
  • Commit the PA6.qmd, and PA6.html files with an explanatory message such as “Created practice activity quarto file”
• Push the changes to the remote repository

Pulling Changes from the Repo

• Git pane > Pull the changes that were made!

Everyone should now have the .qmd and .html files in their local repos!

Making a Change

• Add author: to the YAML and include everyone’s first names
• Render the document
• Git pane > Commit > Stage (or checkmark) files > Commit message > Commit
  • Commit the changes with a message such as “added group first names”
• Push the changes

Pushing Changes & Not Pulling

Do not pull the changes that were made!

Making the Same Change

• Add author: to the YAML and to include everyone’s first and last names.
• Render the document
• Git pane > Commit > Stage (or checkmark) files > Commit message > Commit
  • Commit the changes with a message such as “added group first and last names”
• Push your changes

Forgetting to Pull before you Push

Resolving Merge Conflicts

• Pull the changes from the repo

Resolving Merge Conflicts

Resolving Merge Conflicts

• Review the document with the merge conflict

• Resolve the conflict with the preferred change
• Commit your changes
• Push the changes to the repository

Pushing Changes & Not Pulling

Do not pull the changes that were made!

Making Different Changes

• Change the first code chunk to find the product of 13 times 13.
• Render the document
• Commit your changes
• Push your changes

Auto Merge

Making Different Changes

Do not pull the changes that were made!

Making the Same Changes (Again)

• Change the first code chunk to find the product of 11 times 11.
• Render the document
• Commit your changes
• Push the changes to the repository

Making the Same Changes (Again)

• Pull the changes from the repo
• Review the document with the merge conflict
• Clear the merge conflict by choosing the correct/preferred change
• Commit your changes
• Push you changes

Final Document

Pull, and observe the changes in your document.

Canvas Quiz Submission

Commit Tips

• Use relatively short, but also informative commit messages.
• Commit small blocks of changes. Work to commit every time you’ve accomplished a small task.
  • You’ll have small, bite-sized changes that are briefly described to serve as a record of what you’ve done (and what still needs doing)
  • When you mess up (or end up in a merge conflict) you will have a much easier time pinpointing the spot where things went bad, what code was there before, and (because you have nice, descriptive commit messages) how the error occurred.

Tips for avoiding merge conflicts

When all else fails…

Burn your local repo to the ground and clone again.

To do…

• PA 6: Merge Conflicts
  • Due Thursday, 2/15 at 8:00am
• Midterm Exam
  • Thursday, 2/15
  • Parts 1 & 2 completed during class, Part 3 completed 24 hours after end of class

• Final Project Group Contract
  • Due Thursday, 1/22 at 11:59pm

Thursday, February 15th – Midterm Exam

• I will pass out a sheet with instructions and questions.
• Canvas will unlock online midterm material at the beginning of class.

You are swell!

To do…

• Read Chapter 7: Writing Functions
  • Check-in 7.1 due Tuesday 2/22 at 8am
• Final Project Group Contract
  • Due Thursday 2/22 at 11:59pm